Apparatus for grinding and polishing glass.



No. 891,197. PATENTED JUNE 16, 1908.

F. L. O. WADSWORTH. APPARATUS FOR GRINDING AND POLISHING GLASS.

APPLICATION FILED NOV. 21, 1904 4 SHEETS-SHEET l.

TN ESSES I No. 891,197. PATENTED JUNE 16, 1908.

F. L. O. WADSWORTH.

APPARATUS FOR GRINDING AND POLISHING GLASS.

APPLICATION FILED NOV. 21, 1904.

4 SHEETS-SHEET 2.

mvEm'oR fig &M

WITNESSES No. 891,197. PATENTED JUNE 16, 1908.

F. L. 0. WADSWORTH.

APPARATUS FOR GRINDING AND POLISHING GLASS. APPLICATION FILED Nov. 21,1904.

4 SHEETS-SHEET 3.

wrrnsss .52 mvsn'ron 35a aim PATENTED JUNE 16, 1908.

F. L. 0. WADSWORTH. APPARATUS FOR GRINDING AND POLISHING GLASS.

APPLICATION FILED NOV. 21, 1904.

' 4 SHEETS-SHEET 4.

WITNESSES mvsurqn 554 $1M plying a heating medium .to the table, in theUNITED STATES PATENT OFFICE.

FRANK L. O. \VADSWORTH, OF MORGANTOWN, WEST VIRGINIA;ASSIGNOR TO PRESSEDPRISM PLATE GLASS COMPANY, OF NEW YORK, N. Y., A CORPORATION OF WESTVIRGINIA.

APPARATUS FOR GRINDING AND POLISHING GLASS.

Specification of Lettersliatent. Application flleii November 21, 1904.Serial No. 233,582.

Patented June 16, 1908.

' To all 107mm it may concern:

Be it known that I, FRANK L. 0. Warmwon'rn, of Morgantown, ltlonongaliacounty, West Virginia, have invented a new and useful Apparatus 'forGrinding and Polishing Glass, of which the following is a full, clear,and exact description, reference being had to the accompanying drawings,forming part of this specification, in which Figure 1. is a frontelevation, partly in section of a grinding machine constructed inaccordance with my invention; Fig. 2 is a partial top plan view of thesame; Fig. 3 is an end elevation Fig, 4 is a detail view of the wheelbearings aml'conncctions; Fig. 5 is a bottom plan View of one of thegrinding shoes; Fig. 6 is a partial top plan showing the arrangement oft e polishing blocks; Fig. 7 is a detail View showing the joint betweenthe polisher and its shaft; Fig. 8 is a sectional -side elevationshowing the means for securing the felt. Fig. 9 is a plan viewshowingone arrangement of the tracks and turn-tables, and Pig. 10 is a partialplan view showing another arrangement of the same.

My invention relates to the class of grind ing and polishing machinesfor plate glass, and is designed to increase the speed of the operationand at the same time improve the action of the grinding or polishingsurfaces .upon the glass.

The invention consists in the following features :The use of a floatingsupport for the table spindle, which will allow the table to accommodateitself as the disks move over raised and depressed portions of the glassbeing ground. Further, in the use of a reciprocating carriage carryingfreely rotating grinders which is moved across the table during itsrotation. Also in means for appeculiar arrangement of the grindingshoes, in doing away with the heavy turn-tables for shifting thebridges.

It further consists in the combinations hereinafter described andclaimed.

In the drawings, 2 represents a circular table which may be of ordinaryform, and is mounted upon a vertical spindle 3. The spindle 3 18provided with cylindrical bearing surfaces 4 and 5, the lower one beingmounted in a step hearing of any suitable type.

The surface 4 fits within a bearing in the sta tlonary frame 6 mountedin a pit. Above the bearing 4 a ring 7 secured to the driving spindlerests on a ball-bearing, the ball-race of which is formed in a bearing 8mounted upon a forked lever 9. This lever is pivoted at 10, and isprovided with'a weight 11 which acts against the weight of the table soas to give a lifting pressure. This counterweight therefore affords ayielding su table which will allow it to yie slightly as the grindersmove over the raised and depressed portions of the plates. This avoidsreakage and also gives a more even grinding action. The s )indle willmove up anddown through the cylindrical bearings as the table yieldsduring its rotation. The amount of the counterweight may be varied, butshould be sufficient to afford the yielding action. The, table may berotated by a bevel pinion 12 on a driven shaft 13, which engages a bevelwheel 14 secured to the lower part of the table.

In grinding the glass on the table I em loy a movable bridge 15 carriedupon wheel s 16 movable u on tracks 17. The bearings for these whee sare formed in the lower parts of vertical hollow spindles 18 whichextend up through suitable bearings in the castings 19 forming the endof the bridge. Within each hollow spindle is a driving shaft 20 carryingat its upper end a bevel wheel 20an provided at its lower end with apinion 21 driving a double-toothed wheel 22 having a toothed conicalportion 22 engagin teeth on the face of wheel 16. The wheeTs 20 are)port for the driven by bevel pinions 23 on a common shaft 24 extendingacross the bridge and having hand wheels 25 at each end. manner thebridge may be moved along its tracks, While at the same time casters orsupporting wheels may be turned around on their axes for a purposehereinafter explained.

The grinding disks are not supported directly upon the bridge, but arecarried upon a reciprocating frame or carriage 26 having upper wheels 27resting upon tracks 28 extending through the bridge. The grindercarriage hangs upon these rollers or wheels and is reciprocated by apitman 29 extending to a crank 30 on a shaft 31 having gear wheel 32driven by a pinion 33 on shaft 34 carrying the pulley 35 by which theshaft is driven. The belt for this pulley is arranged so that it willallow for the movement of the carriage.

The carriage is guided during its reciprocation by side rollers 36movable upon guides In this 37 on the bridge The rollers 36 are mountedupon small stub shaft ends which are eccentric to the shafts 36', sothat by turning the shafts I can adjust-the guide rollers'to make theface of the grinders parallel with the table. The spindles 38 for thegrinding disks 39 are mounted in the ordinary manner upon the recirocating carriage, being adjustable by t e levers 40 engaged by thescrew-shafts 41 having lower ha-n wheels 42.

The reciprocating of the grinder carriage makes the grinding moreuniform, since any point on the face of the grinder constantly changesosition relative to the axis of rotation of t e table. Hence, thegrinding does shoe. These s oes may be cast interchangeably so that theycan be removed and replaced without removing and turning over thegrinding runners.-

The lower face. of the casting is provided with a series of grooves 45,the general direction of which is inclined both to the radius andcircumference of the general circle of the disk. The grooves are alsopreferably made in zig-zag or sinuous form, as shown, so that the sandwill travel through them at an uneven rate. It travels faster in thosearts approaching circumferential lines, and s ower in the partsapproaching the radial lines. This retains the sand for short intervalsof time, in the radial portions of the grooves, and makes the grindmgaction-more ra id.

As the movement of the table is in the same direction as that of thedisks and at a higher speed, the motion of the table will force the sandthrough the grooves at one side of the segment and suck it through'thegrooves on the opposite side, at any given moment. The movement of thesand through the grooves is therefore made positive and the grindingaction more rapid.

Another feature of m invention lies in providing means for a p ying aheatin medium to the table. hen-the glass is ein polished its uppersurfacebecomes heate and the difference in temperature between its u perand lower faces sometimes warps the g ass and cracks it. Moreover, glassWlll not polish roperly until its temperature has been raise andordinarily this is done by the friction of the polishers themselves.This heating up consumes a considerable amount of time, in addition tothe liability of cracking the glass. i

provide means for heating the table, preferably by introducing steam orhot water nects through through the hollow supporting spindle,circulating' it through the table, and then drawing it away throughanother passage in the hollow shaft or spindle. Thus, in Fig. 1' I showthe spindle 3 as provided with two hollow stuffing boxes 53 and 54, intoone of which s'team or'hot water is supplied through a pipe 55, whilethe steam passes out from the other through pipe 56. A vertical assageextends through the spindle from the 0x53 and coni 'e 57 with a cavityin the body of the ta e. This cavity preferably extends throughout thepolishing surface of the table, and 1s divided by the centraltransversepartition 58,-having holes 59 at op 0- site ends near the ed eof the table. he steam entering throug pipe 57 passes out in the chamberon one side and then flows through the holes 59 in the other chamber,and after thus circulating beneath the whole surface of the table itpasses down through pipe 60.into another passage in the shaft 3 whichleads to stufiing box 54. I can thus maintain a circulation of steam orother heating fluid through the table at the beginning of the polishingoperation and us heat the lower face of the lass and at the same timeincrease thespee of olishing. I may also a ly this heating me ium at anyother desirabls times in the operation. 7

In the ordinary systems where traveling bridges are used the entirebridge is moved out 1n front of one table onto a large turntable andthen turned around at rlght angles, moved laterally in front of the nexttable onto another large turn-table, and then turned around forward overthis next table. In such systems the turn-tables are large and heavy andoccupy a large amount of space. In some cases a grinding bridge and a;olishing bridge are used for each table and/part of these bridges wereidle a large part of the time.

I have done away with the large, heavy turn-tables, and employ insteadof them small turn-tables on which the supporting wheels of the bridgerest when run out in front of the table. Thus, I show in Fig. 9' foursmall turn-tables 46, which are arranged to receive the supportingwheels of the 1 brid e. The bridge wheels being on rotary s in les, whenthe small tables are turned t e wheels turn with them to bring them intoalinement with the cross track 47. The bridges then run sidewise infront of the other table onto a similar four turn-table device, wherethe wheels are again shifted and the bridge then run forward over thenext table. This system enables one grinding and one polishin bridge tosupply several tables, 125 thus re ucing the cost of the system aneconomizing s ace, as the four small tablf s take up much ess room thanthe single le ffge table.

In the preferred form of Fig. 10, the pol-, 1,30

1 small turn tables 46 are used at the ends of each track and I can thususe each bridge successively for-a series of tables without shifting itfor each table as in the form of Fig. 9.

The polishing bridge may be of any ordinary type, except as to thefeatures above named, and I have improved the polishing disk in twofeatures.

polishing disk and. its stem, in combination with a disk-bearing whichgives the disk a free rotation independent of the ball and socket joint.Thus, inFig. 7 I show the olishing disk 48 as connected to its stem 49 8ball and socket joint 50. A bearing 51 is a so provided for the diskwhich surrounds the ball joint and supports the disk so that the diskrotates on this bearing while the ball joint allows universaladjustment. The advantage of this feature lies in giving free rotationwhile the table is rotating. Where the ball and socket joint alone isused the disk is liable to bind under the pushing action of the. table;but by combining theball and socket joint with an inde endent bearing Iobtain free rotation of the isk, while at the same time the disk'canadjust itself to the table. The two half boxes for the disk bearing areclamped together edge to edge, their lower ends loosely engaging the hubof the disk.

Another feature in the olishing disk lies in the manner of securing t 1efelt or cloth on the disk. Instead of using a plain edge on the disk,around which the felt is secured by the frictional action of a ring, Icut notches 52 in the edge of the disk as shown in F ig. 8, thesenotches being sha ed to receive the corner portions of the fe t. Thenotches are preferably of slightly less depth than the thickness of thefelt so that as the ring is forced u over the disk it will bear onlyagainst t e corner portions of the felt and force them into the notches.This gives a positive seating of the felt to prevent its turning aroundthe disk, and also economizes space and gives a larger effectiveolishing area for the size of the polisher t an heretofore.

The advantages of my invention will be understood by those skilled inthe art, from the preceding descriptionf The floating action of thetable gives uniform action and avoids breakage. The reciprocating of thegrinder also assists in giving uniform grinding and affords a smoothersurface. The peculiar arrangement of the shoes increases the speed ofgrinding and gives more efiicient action of the abrading medium. Theheating of the table equalizes the temperature of the glass on bothsides during the polishing operation and prevents liability to cracking;

The-

The first consists inthe use of a ball and socket joint between thewhile it also facilitates the polishing action by bringing the glassmore quickly to the temperature required for effective polishing action.The track system economizes space and original cost, as well as thetime'occupied in changing bridges. The peculiar bearing of thepolishing-spindle allows free rotation and also automatic adjustment,while the felt-securing means is simple and effecttive, and more securethan former devices.

Those features of the machine which are herein shown and described, butnot claimed herein, form the subject of divisional applications whichhave been filed by me therefor. These applications are Serial No.255,863, filedApril17th, 1905; Serial No. 266,696 filed June 24th, 1905;and Serial No. 332,203, filed the operation of grinding or polishing,and

means for permitting automatic adjustment of said table to correspond tothe vertical movements of the disk with respect to said disks during thegrinding or polishing action so as to secure uniform pressure on theobject being ground or polished; substantially as described.

2. In grinding or polishing apparatus, a freely rotating and verticallymoving grinding or polishing disk, a table arranged to rotate the diskduring the operation of grinding or polishing, means for rotating thetable, and a counterweight for partially counterbalancing the table topermit its automatic adjustment towards and away from the freelyrotating disk during the grinding or polishing action to correspond tothe vertical movements of the disk so as to secure a uniform pressureupon the object being ground or polished; substantially as described.

3. In grinding or polishing apparatus, a table, means for rotatingthesame, a freely rotating grinding or polishing disk, means forpermitting automatic adjustment of said table with respect to said disk,a reciprocable carriage carrying the disk, a bridge or support uponwhich the carriage is mounted and means for reciprocating the carriageduring the rotation of the table; substantially as described.

4. In grinding or polishing apparatus, a table, means for rotating thesame, a carriage having freely rotating disks, and means forreciprocating the carriage during rotation of the table; substantiallyas described.

5. In a grinding or polishing apparatus, a table, means for rotating thesame, a bridge movable to and from the table, a carriage movable alongthe bridge, and means for reciprocating the carnage durlng rotatlon ofthe table; substantially as described.

6. In a'grinding or polishing apparatus, a rotary table, a bridgemovable thereover, a carriage movable lengthwise of the bridge andcarrying grinding disks, and connections for reciprocating the carriagewhen the bridge is in position over the table; substantially asdescribed.

7. In rinding or polishing apparatus, a rotary ta le, a bridge movablethereover, a carriage movable along the bridge, and means for adjustingthe carriage transversely; substantially as described.

7 8. ha grinding or polishing system, a traveling bridge havingvertically extending rotary stemsyand supporting Wheels for the bridgecarried upon said stems and means for positively actuating the saidstems; substantially as described.

9. In a grinding or polishing system, a

traveling bridge having vertically extending rotaryspindles, supportingWheels for the bridge mountedin the spindles, and positive means forturning said wheels on their axes;

FRANK L. O. WADSWORTH.

Witnesses:

G. M. VIERS, H M. CoRwIN.

